scholarly journals Allometry measurements from in situ video recordings can determine the size and swimming speeds of juvenile and adult squid Loligo opalescens (Cephalopoda: Myopsida)

2004 ◽  
Vol 207 (24) ◽  
pp. 4195-4203 ◽  
Author(s):  
L. D. Zeidberg
Keyword(s):  
Loligo Opalescens ◽  
Video Recordings

scholarly journals Pelagic deep-sea fauna observed on video transects in the southern Norwegian Sea

Polar Biology ◽  
2021 ◽  
Author(s):  
Philipp Neitzel ◽  
Aino Hosia ◽  
Uwe Piatkowski ◽  
Henk-Jan Hoving
Keyword(s):  
First Record ◽  
Observation System ◽  
In Situ Observation ◽  
Norwegian Sea ◽  
Video Recordings ◽  
In Situ Observations ◽  
Abundance And Distribution ◽  
Oceanic Food Webs ◽  
Deep Sea Fauna

AbstractObservations of the diversity, distribution and abundance of pelagic fauna are absent for many ocean regions in the Atlantic, but baseline data are required to detect changes in communities as a result of climate change. Gelatinous fauna are increasingly recognized as vital players in oceanic food webs, but sampling these delicate organisms in nets is challenging. Underwater (in situ) observations have provided unprecedented insights into mesopelagic communities in particular for abundance and distribution of gelatinous fauna. In September 2018, we performed horizontal video transects (50–1200 m) using the pelagic in situ observation system during a research cruise in the southern Norwegian Sea. Annotation of the video recordings resulted in 12 abundant and 7 rare taxa. Chaetognaths, the trachymedusaAglantha digitaleand appendicularians were the three most abundant taxa. The high numbers of fishes and crustaceans in the upper 100 m was likely the result of vertical migration. Gelatinous zooplankton included ctenophores (lobate ctenophores,Beroespp.,Euplokamissp., and an undescribed cydippid) as well as calycophoran and physonect siphonophores. We discuss the distributions of these fauna, some of which represent the first record for the Norwegian Sea.

Wave Breaking Dissipation in a Young Wind Sea

2014 ◽  
Vol 44 (1) ◽  
pp. 104-127 ◽  
Author(s):  
Michael Schwendeman ◽  
Jim Thomson ◽  
Johannes R. Gemmrich
Keyword(s):  
Wind Waves ◽  
Phase Speed ◽  
Field Studies ◽  
Turbulent Energy ◽  
Strength Parameter ◽  
Video Recordings ◽  
Sonar System ◽  
Wind Sea ◽  
Equilibrium Range

Abstract Coupled in situ and remote sensing measurements of young, strongly forced wind waves are applied to assess the role of breaking in an evolving wave field. In situ measurements of turbulent energy dissipation from wave-following Surface Wave Instrument Float with Tracking (SWIFT) drifters and a tethered acoustic Doppler sonar system are consistent with wave evolution and wind input (as estimated using the radiative transfer equation). The Phillips breaking crest distribution Λ(c) is calculated using stabilized shipboard video recordings and the Fourier-based method of Thomson and Jessup, with minor modifications. The resulting Λ(c) are unimodal distributions centered around half of the phase speed of the dominant waves, consistent with several recent studies. Breaking rates from Λ(c) increase with slope, similar to in situ dissipation. However, comparison of the breaking rate estimates from the shipboard video recordings with the SWIFT video recordings show that the breaking rate is likely underestimated in the shipboard video when wave conditions are calmer and breaking crests are small. The breaking strength parameter b is calculated by comparison of the fifth moment of Λ(c) with the measured dissipation rates. Neglecting recordings with inconsistent breaking rates, the resulting b data do not display any clear trends and are in the range of other reported values. The Λ(c) distributions are compared with the Phillips equilibrium range prediction and previous laboratory and field studies, leading to the identification of several inconsistencies.

scholarly journals A stab in the dark: chick killing by brood parasitic honeyguides

2011 ◽  
Vol 8 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Claire N. Spottiswoode ◽  
Jeroen Koorevaar
Keyword(s):  
Parental Care ◽  
Electronic Supplementary Material ◽  
Total Darkness ◽  
Brood Parasites ◽  
Video Recordings ◽  
Supplementary Material ◽  
Host Killing ◽  
Host Death ◽  
Human Hands

The most virulent avian brood parasites obligately kill host young soon after hatching, thus ensuring their monopoly of host parental care. While the host eviction behaviour of cuckoos (Cuculidae) is well documented, the host killing behaviour of honeyguide (Indicatoridae) chicks has been witnessed only once, 60 years ago, and never in situ in host nests. Here, we report from the Afrotropical greater honeyguide the first detailed observations of honeyguides killing host chicks with their specially adapted bill hooks, based on repeated video recordings (available in the electronic supplementary material). Adult greater honeyguides puncture host eggs when they lay their own, but in about half of host nests at least one host egg survived, precipitating chick killing by the honeyguide hatchling. Hosts always hatched after honeyguide chicks, and were killed within hours. Despite being blind and in total darkness, honeyguides attacked host young with sustained biting, grasping and shaking motions. Attack time of 1–5 min was sufficient to cause host death, which took from 9 min to over 7 h from first attack. Honeyguides also bit unhatched eggs and human hands, but only rarely bit the host parents feeding them.

Photoemission Electron Microscopy Experiments with the Balzers Ke3 Metioscope

1990 ◽  
Vol 48 (1) ◽  
pp. 571-571
Author(s):  
C. Hammond ◽  
M. A. Imam
Keyword(s):  
Surface Oxidation ◽  
Low Carbon ◽  
Photoelectron Emission ◽  
Video Recordings ◽  
Fluorescent Screen ◽  
Alloy Steels ◽  
Ferrite Nucleation ◽  
Argon Ion ◽  
Photoemission Electron

In the Balzers KE3 ’Metioscope’, photoelectron emission is stimulated by the action of four mercury arc U.V. lamps, the light from which is reflected onto the specimen surface from the anode plate. The specimen may be heated in a wire-wound furnace enclosure or by an electron beam. In both cases temperatures of the order of 1200°C are attainable. Surface oxidation and contamination may be removed in situ by the use of an argon ion and/or neutral particle gun. The emitted electrons are imaged using electromagnetic lenses onto a fluorescent screen which is linked to a TV camera and recorder. Hence dynamic changes occurring at high temperatures or during heating or cooling may be recorded continuously.This paper will first briefly review recent published and unpublished work carried out using the Metioscope, which illustrate both the capabilities and limitations of the technique. Secondly, the results of a series of on-going experiments on ferrite nucleation and growth from austenite grain boundaries in low carbon alloy steels will be described and illustrated with video-recordings. The steels were austenitised at 975-950°C and either (a) rapidly cooled at 775-725°C and transformed isothermally or (b) continuously cooled at rates in the range 0.5-0.05°C/sec.

Respecifying the information sheet

2020 ◽  
Vol 14 (2) ◽  
pp. 127-148
Author(s):  
Brian L. Due
Keyword(s):  
Decision Making ◽  
Conversation Analysis ◽  
Joint Attention ◽  
Service Encounter ◽  
Information Sheet ◽  
Shared Resource ◽  
Video Recordings ◽  
Decision Making Processes ◽  
Large Corpus

This paper considers how information sheets are used as a resource for joint attention and decision-making in a situated service encounter. The optician shop is a perspicuous setting for addressing decision-making as an interactional accomplishment informed by information sheets, because they are routinely used and made relevant by sellers. The paper builds on ethnomethodological multimodal conversation analysis and a large corpus of more than 700 hours of video recordings from eleven different Danish optician shops. Based on one single analysis from this corpus, the paper shows how the sheet is used cooperatively and oriented to in situ as a shared resource in the process of selling/buying glasses. A key finding is that the information sheet is not just a resource for the seller but a shared resource for established joint attention and decision-making. More generally, the paper contributes to studies of service and sales encounters by highlighting the importance of inscribed objects to decision-making processes in social interaction.

scholarly journals Attending to the Mobile Text Summons: Managing Multiple Communicative Activities Across Physically Copresent and Technologically Mediated Interpersonal Interactions

2018 ◽  
Vol 47 (5) ◽  
pp. 669-700
Author(s):  
Stephen M. DiDomenico ◽  
Joshua Raclaw ◽  
Jessica S. Robles
Keyword(s):  
Mobile Phone ◽  
Interpersonal Communication ◽  
Technology Use ◽  
Text Message ◽  
Short Message ◽  
Mobile Phone Use ◽  
Video Recordings ◽  
Message Service ◽  
Communication Practices

This article presents a qualitative investigation of communication practices interactants use to manage mobile phone activity while they are engaged in a copresent conversation. Drawing from conversation analysis and a collection of naturalistic video recordings, our study of mobile phone use in situ focuses on how participants orient to the mobile text summons, the audible chimes or vibrations that indicate the receipt of a text message (or short message service [SMS]). In these moments, interactants must simultaneously manage attending to their phone and the copresent conversation. Our analysis shows how people may use nonverbal and verbal techniques to attend to their mobile phone based on their identity respective to the copresent activity. The study contributes to scholarly understandings of technology use, multitasking, and the management of attention in interpersonal communication.

Swimming in the Antarctic scallop Adamussium colbecki: analysis of in situ video recordings

1998 ◽  
Vol 10 (4) ◽  
pp. 369-375 ◽  
Author(s):  
Alan D. Ansell ◽  
Riccardo Cattaneo-Vietti ◽  
Mariachiara Chiantore
Keyword(s):  
Ross Sea ◽  
Maximum Velocity ◽  
Remotely Operated Vehicle ◽  
Mean Velocity ◽  
Terra Nova Bay ◽  
Video Recordings ◽  
Swimming Trajectories ◽  
Opening And Closing ◽  
The Antarctic

Swimming activity of the Antarctic scallop at a temperature of c. −1.4°C was analysed using in situ video recordings obtained from a remotely operated vehicle (ROV) in Terra Nova Bay, Ross Sea. Data are presented on swimming trajectories, distance travelled and velocity during a swimming bout, adduction frequency, shell gape angle, and the angular opening and closing velocities of shell. This scallop is an effective swimmer although swimming bouts in response to the ROV were generally short, consisting of 2–5 adduction cycles in the take-off phase followed by 1–4 (exceptionally 14) adductions during level swimming. The maximum velocity during each adduction cycle ranged from 19.4–43.1 cm s−1 and the mean velocity during a swimming bout from 12.0–23.5 cm s−1. Each adduction cycle consists of opening, closing and glide phases of approximately equal duration. Adduction frequency during swimming averaged 1.5 adductions s−1.

Acoustical Assessment of Squid (Loligo opalescens) off the Central Oregon Coast

1987 ◽  
Vol 44 (6) ◽  
pp. 1261-1267 ◽  
Author(s):  
Katharine Jefferts ◽  
Janusz Burczynski ◽  
William G. Pearcy
Keyword(s):  
Geographic Distribution ◽  
Distribution Density ◽  
Strength Distribution ◽  
Target Strength ◽  
Adjacent Area ◽  
Density Estimates ◽  
Oregon Coast ◽  
Loligo Opalescens ◽  
Dual Beam

Squid (Loligo opalescens) were surveyed acoustically in an area off the Oregon coast using dual-beam and echo integrator techniques. The method developed is shown to be feasible for in situ estimation of target strength, distribution, and abundance of midwater squids. Average target strength was estimated both while drifting with a squid school and cruising over one. The values derived, −58.6 to −58.7 dB, are much lower than previous estimates, but more realistic in relation to the target strength of fishes. Schools judged to be fish or squid showed little difference in depth or size, but varied significantly in geographic distribution. Density estimates ranged from 9.9 t/km2 in a known spawning area to 0.93 t/km2 in an adjacent area.

An ethogram of the Humboldt squid Dosidicus gigas Orbigny (1835) as observed from remotely operated vehicles

Behaviour ◽  
2015 ◽  
Vol 152 (14) ◽  
pp. 1911-1932 ◽  
Author(s):  
Lloyd A. Trueblood ◽  
Sarah Zylinski ◽  
Bruce H. Robison ◽  
Brad A. Seibel
Keyword(s):  
Open Ocean ◽  
The Body ◽  
Dosidicus Gigas ◽  
Remotely Operated Vehicles ◽  
Functional Roles ◽  
Video Recordings ◽  
Humboldt Squid ◽  
Body Patterns ◽  
Body Pattern

Many cephalopods can rapidly change their external appearance to produce multiple body patterns. Body patterns are composed of various components, which can include colouration, bioluminescence, skin texture, posture, and locomotion. Shallow water benthic cephalopods are renowned for their diverse and complex body pattern repertoires, which have been attributed to the complexity of their habitat. Comparatively little is known about the body pattern repertoires of open ocean cephalopods. Here we create an ethogram of body patterns for the pelagic squid, Dosidicus gigas. We used video recordings of squid made in situ via remotely operated vehicles (ROV) to identify body pattern components and to determine the occurrence and duration of these components. We identified 29 chromatic, 15 postural and 6 locomotory components for D. gigas, a repertoire rivalling nearshore cephalopods for diversity. We discuss the possible functional roles of the recorded body patterns in the behavioural ecology of this open ocean species.

scholarly journals GRAIN-GRAIN INTERACTION IN OSCILLATING SHEETFLOW

1988 ◽  
Vol 1 (21) ◽  
pp. 53 ◽  
Author(s):  
W.T. Bakker ◽  
W.G.M. Van Kesteren ◽  
Z.H. Yu
Keyword(s):  
High Speed ◽  
Video Recordings ◽  
Measuring Devices ◽  
Ring Shear ◽  
Grain Interaction ◽  
Lateral Mixing ◽  
Ring Shear Apparatus ◽  
Neutrally Buoyant ◽  
Intrusion Depth

Viscous grain-grain interaction is an important aspect of the dynamics of oscillating sheetflow. This interaction between sand grains has been investigated qualitatively in a pulsating water tunnel. Furthermore, experiments concerning the interaction between neutrally buoyant spheres in a Couette flow have been carried out at a scale of 100:1 in a new developed ring shear apparatus, called " Carrousel." With respect to the dynamics of sheetflow, in-situ measuring devices for the sand concentration in the sheetflow ("Harp") and the bed load ("Swan") has been developed; some preliminary results are shown. For sand grains, the intrusion depth of sheetflow appears to be of the order of several mm. On high speed video recordings no lateral mixing between grain layers can be observed; for this some physical explanation is given. This supports the modelling of the sheetflow mechanism as moving grain layers.

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